[tip:perf/urgent] perf/x86: Add constraint for IVB CYCLE_ACTIVITY:CYCLES_LDM_PENDING

[tip-bot for Stephane Eranian]

Commit-ID:  6113af14c82726d5a2993a7ba238df24c990a5ee
Gitweb:     http://git.kernel.org/tip/6113af14c82726d5a2993a7ba238df24c990a5ee
Author:     Stephane Eranian <eranian@xxxxxxxxxx>
AuthorDate: Wed, 11 Sep 2013 08:22:22 -0700
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 12 Sep 2013 07:58:26 +0200

perf/x86: Add constraint for IVB CYCLE_ACTIVITY:CYCLES_LDM_PENDING

The IvyBridge event CYCLE_ACTIVITY:CYCLES_LDM_PENDING can only
be measured on counters 0-3 when HT is off. When HT is on, you
only have counters 0-3.

If you program it on the eight counters for 1s on a 3GHz
IVB laptop running a noploop, you see:

           2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
           2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
           2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
           2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
       3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
       3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
       3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
       3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING

Clearly the last 4 values are bogus.

Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: peterz@xxxxxxxxxxxxx
Cc: ak@xxxxxxxxxxxxxxx
Cc: zheng.z.yan@xxxxxxxxx
Cc: dhsharp@xxxxxxxxxx
Link: http://lkml.kernel.org/r/20130911152222.GA28761@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/kernel/cpu/perf_event_intel.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 0abf674..c62d883 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -124,6 +124,7 @@ static struct event_constraint intel_ivb_event_constraints[] __read_mostly =
 	INTEL_UEVENT_CONSTRAINT(0x0148, 0x4), /* L1D_PEND_MISS.PENDING */
 	INTEL_UEVENT_CONSTRAINT(0x0279, 0xf), /* IDQ.EMTPY */
 	INTEL_UEVENT_CONSTRAINT(0x019c, 0xf), /* IDQ_UOPS_NOT_DELIVERED.CORE */
+	INTEL_UEVENT_CONSTRAINT(0x02a3, 0xf), /* CYCLE_ACTIVITY.CYCLES_LDM_PENDING */
 	INTEL_UEVENT_CONSTRAINT(0x04a3, 0xf), /* CYCLE_ACTIVITY.CYCLES_NO_EXECUTE */
 	INTEL_UEVENT_CONSTRAINT(0x05a3, 0xf), /* CYCLE_ACTIVITY.STALLS_L2_PENDING */
 	INTEL_UEVENT_CONSTRAINT(0x06a3, 0xf), /* CYCLE_ACTIVITY.STALLS_LDM_PENDING */
--
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